Work out concrete curing time instantly with clear inputs, formula shown and shareable results.
Inverting the ACI maturity relation gives the age at which a target fraction of 28 day strength is reached: t = a x R / (1 - b R). Warmer concrete matures faster, so the reference time is scaled by the square root of the ratio of 20 °C to the actual curing temperature. Codes still require a minimum wet curing period regardless of strength gain.
Age for target strength
t = a x R / (1 - b x R), R = target fraction of fc28
Temperature adjustment
t adjusted = t at 20 °C x sqrt(20 / T)
Preliminary estimate only. Curing periods must follow the applicable concrete code and specification, not a strength estimate alone.
t = a x R / (1 - b x R), R = target fraction of fc28. Inverting the ACI maturity relation gives the age at which a target fraction of 28 day strength is reached: t = a x R / (1 - b R).
Curing protects against plastic and drying shrinkage cracking and develops the surface zone that resists carbonation and chloride ingress. Those benefits do not appear in a cube strength number.
This calculator takes 3 inputs: Target share of 28 day strength, Average curing temperature, Cement type. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.